This invention relates to a semiconductor light emitting element, manufacturing thereof, integrated semiconductor light emitting device, manufacturing method thereof, image display device, manufacturing method thereof, illuminating device and manufacturing method thereof, which are especially suitable for application to light emitting diodes using nitride III-V compound semiconductors.
A light emitting diode as a semiconductor light emitting element has been proposed. This semiconductor light emitting element was made by growing an n-type GaN layer on a sapphire substrate; next forming thereon a growth mask having a predetermined opening; selectively growing an n-type GaN layer in form of a six-sided pyramid having an inclined crystal plane inclined from the major surface of the substrate, i.e. having an S-oriented plane; and growing an active layer, p-type GaN layer and other layers on the inclined crystal plane (see, for example, brochure of International Publication No. 02/07231 (pages 47-50 and FIGS. 3-9)). This light emitting diode can prevent propagation of penetrating dislocations from the substrate side to layers composing the element structure, and can improve the crystalline property of these layers, high emission efficiency can be obtained.
FIGS. 1A and 1B show a typical semiconductor light emitting element disclosed in the above-mentioned literature. This semiconductor light emitting element is manufactured by the following method. An n-type GaN layer 102 is first grown on a sapphire substrate 101 having a C+ oriented major surface. After that, a SiO2 film is formed on the entire surface of the n-type GaN layer 102, and it is patterned by lithography and etching to make a growth mask 104 having an opening of a predetermined geometry in a position for forming the element. The geometry of the opening 103 is a circle or a hexagon having one side parallel to the <11-20> direction. Size of the opening 103 is about 10 μm. In the next step, under the existence of the growth mask 104, an n-type GaN layer 105 is selectively grown on a part of the n-type GaN layer 102 exposed through the opening 103. As a result of the selective growth, the n-type GaN layer 105 is in form of a six-sided pyramid. Six planes of the six-sided pyramidal n-type GaN layer 106 are S-oriented planes inclined from the major surface of the sapphire substrate 101. After that, an active layer 106 composed of InGaN compounds, for example, and a p-type GaN layer 107 are sequentially grown on the n-type GaN layer 105. Through these steps, here is obtained a double-hetero-structured light emitting diode structure including the six-sided pyramidal n-type GaN layer 105, active layer 106 and p-type GaN layer 107, the last two being grown sequentially on the inclined crystal planes of the six-sided pyramidal n-type GaN layer 105. In the next step, which is not explained here in detail, a p-side electrode is formed on the p-type GaN layer 107 and an n-side electrode is formed on the n-type GaN layer.
Existing semiconductor light emitting elements, having a light emitting element structure made by selectively growing the six-sided pyramidal n-type GaN layer 105 having an S-oriented inclined crystalline plane and next growing the active layer 106 and the p-type GaN layer 107 on the S-oriented plane, were unsatisfactory in light emitting efficiency, and inevitably required a large occupied area per each element.